This invention relates to the removal of oxygen from aqueous system such as boiler feedwater and oil well injection water. Such oxygen removal is achieved with erythorbic acid, erythorbate, ascorbic acid, or ascorbate, with the aid of activated carbon.
The use of erythorbic acid as an oxygen remover or scavenger in boiler feedwater is described in Kelly et al U.S. Pat. No. 4,419,327. At the high temperatures and pressures of the boiler system, erythorbic acid is capable of reacting with oxygen very rapidly in the absence of activated carbon. At ambient temperature, however, erythorbic acid reacts too slowly to be of practical value.
Meyers et al U.S. Pat. No. 4,627,921 discloses deoxygenation of water at ambient temperature by passing the water with a reducing agent such as hydrazine, morpholine, sodium sulfite, and sodium acid sulfite through an adsorbent, absorbent bed which may be made of activated carbon. The present invention introduces further oxygen scavengers having advantages not attained with the above four reducing agents of Meyers et al.